The present invention relates generally to the use of surfactant compositions to clean contact lenses. More particularly, it relates to the use of a surfactant composition which is composed of a combination of surfactants that make it an effective cleansing agent, but with non-irritating properties such that it lacks significant irritating characteristics when in contact with periocular and ocular surface tissues.
As disclosed in our copending application Ser. No. 034,043, filed Apr. 3, 1987, for some time a desirable surfactant product has been sought in which the advantageous foaming properties of an anionic surfactant can be maintained while avoiding the irritation to the skin that such surfactants normally cause. The characteristic of irritating sensitive human skin and membranes is particularly evident when the surfactant is to be utilized in the vicinity of the human eye. Such surfactants or shampoos have previously been utilized to help in the control of oily debris, cosmetics and encrusted material that may form on the scalp and face. Yet there is definite need for a surfactant composition for use in conditions requiring good eyelid and eyelash cleansing.
An example of one such condition is acute and chronic blepharitis. Blepharitis is an inflammation of the eyelids that arises in the glands found at the base of the eyelashes (glands of Zeis and Moll) and just behind the eyelashes (meibomian glands). These glands secrete an oily lipid material (meibom), which is essential for maintenance of the normal tear film on the ocular surface as well as the natural lubrication of the eyelids. When these glands become inflamed or clogged by thickened secretions, cosmetics, infection, or other causes not yet identified, the surrounding tissues become inflamed. The resulting inflammation of the eyelids and ocular surface is called blepharitis and can produce a variety of symptoms of ocular dysfunction. These symptoms may include but not be limited to any or all of the following: irritation, itching, burning, dryness, tearing, redness of the eyelids and conjunctiva, filmy vision, chalazion or hordeolum formation, and loss of eyelashes. Severe cases can even produce corneal opacification and decreased vision.
The mainstay of present therapy for blepharitis is the combined use of warm compresses and daily lid hygiene to clean the oily secretions, crusting and other forms of debris which accumulate on the eyelids and eyelashes, thereby exacerbating the inflammatory problem. Certain oral and topical medications are then added to this primary therapy as needed in each individual case. However, at present there is no cleansing surfactant product specifically designed for use by the patient to clean the eyelids and eyelashes. Therefore eye care professionals currently recommend the use of mineral oil or mild hair shampoos. These shampoos must be diluted by the patient with water to reduce the irritancy of the cleansing component in the shampoo. Despite using dilute hair shampoos, many patients develop a secondary ocular irritation from the cleansing agents, themselves. These shampoos have the additional disadvantage of containing dyes and/or perfumes which do not enhance the cleansing potential but may act as ocular irritants.
It has now been found that the surfactant that is the subject of our copending application is especially adapted for use in removing mucus, lipids or other proteinaceous materials from the surface of a contact lens, either by immersing the contact lens in the surfactant solution, or by applying said surfactant solution to the contact lens while it is in place on the eye of the wearer. It is, therefore, a primary object of the present invention to provide a process or method of using the surfactant composition that maintains the foaming and cleansing characteristics of an anionic surfactant, while at the same time significantly ameliorating the irritating characteristcs of such anionics, as a contact lens cleaner. This surfactant composition is specifically suitable for such use.
These and other objects of the present invention will become more apparent to one of skill in this art from the summary and detailed description of the invention provided hereinafter.